Commit 78251639 authored by Suman Anna's avatar Suman Anna Committed by Santosh Shilimkar
Browse files

soc: ti: pruss: Add support for PRU-ICSSs on AM437x SoCs 



The AM437x SoCs have two different PRU-ICSS subsystems: PRU-ICSS1
and a smaller PRU-ICSS0. Enhance the PRUSS platform driver to support
both the PRU-ICSS sub-systems on these SoCs.

The PRU-ICSS1 on AM437x is very similar to the PRU-ICSS on AM33xx
except for few minor differences - increased Instruction RAM, increased
Shared Data RAM2, and 1 less interrupt (PRUSS host interrupt 7 which is
redirected to the other PRUSS) towards the MPU INTC. The PRU-ICSS0 is
a cut-down version of the IP, with less DRAM per PRU, no Shared DRAM etc.
It also does not have direct access to L3 bus regions, there is a single
interface to L3 for both PRUSS0 and PRUSS1, and it would have to go
through the PRUSS1's interface. The PRUSS_SYSCFG register is reserved on
PRUSS0, so any external access requires the programming the corresponding
PRUSS_SYSCFG register in PRUSS1. It does have its own dedicated I/O lines
though. Note that this instance does not support any PRU Ethernet related
use cases.

The adaptation uses SoC-specific compatibles in the driver and uses
a newly introduced pruss_match_private_data structure and the
pruss_get_private_data() function to retrieve a PRUSS instance specific
data using a device-name based lookup logic. The reset and the L3 external
access are managed by the parent interconnect ti-sysc bus driver so that
PRUSS1 and PRUSS0 can be independently supported.

Signed-off-by: default avatarSuman Anna <s-anna@ti.com>
Signed-off-by: default avatarAndrew F. Davis <afd@ti.com>
Signed-off-by: default avatarGrzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: default avatarSantosh Shilimkar <santosh.shilimkar@oracle.com>
parent dc112956

drivers/soc/ti/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ config TI_K3_SOCINFO 


config TI_PRUSS

	tristate "TI PRU-ICSS Subsystem Platform drivers"

	depends on SOC_AM33XX

	depends on SOC_AM33XX || SOC_AM43XX

	select MFD_SYSCON

	help

	  TI PRU-ICSS Subsystem platform specific support.

drivers/soc/ti/pruss.c

+34 −1
Original line number Diff line number Diff line
@@ -17,6 +17,14 @@ 
#include <linux/pm_runtime.h>

#include <linux/pruss_driver.h>



/**

 * struct pruss_private_data - PRUSS driver private data

 * @has_no_sharedram: flag to indicate the absence of PRUSS Shared Data RAM

 */

struct pruss_private_data {

	bool has_no_sharedram;

};



static int pruss_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;
@@ -25,8 +33,15 @@ static int pruss_probe(struct platform_device *pdev) 
	struct pruss *pruss;

	struct resource res;

	int ret, i, index;

	const struct pruss_private_data *data;

	const char *mem_names[PRUSS_MEM_MAX] = { "dram0", "dram1", "shrdram2" };



	data = of_device_get_match_data(&pdev->dev);

	if (IS_ERR(data)) {

		dev_err(dev, "missing private data\n");

		return -ENODEV;

	}



	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));

	if (ret) {

		dev_err(dev, "failed to set the DMA coherent mask");
@@ -45,7 +60,14 @@ static int pruss_probe(struct platform_device *pdev) 
		return -ENODEV;

	}



	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {

	for (i = 0; i < PRUSS_MEM_MAX; i++) {

		/*

		 * On AM437x one of two PRUSS units don't contain Shared RAM,

		 * skip it

		 */

		if (data && data->has_no_sharedram && i == PRUSS_MEM_SHRD_RAM2)

			continue;



		index = of_property_match_string(child, "reg-names",

						 mem_names[i]);

		if (index < 0) {
@@ -126,8 +148,19 @@ static int pruss_remove(struct platform_device *pdev) 
	return 0;

}



/* instance-specific driver private data */

static const struct pruss_private_data am437x_pruss1_data = {

	.has_no_sharedram = false,

};



static const struct pruss_private_data am437x_pruss0_data = {

	.has_no_sharedram = true,

};



static const struct of_device_id pruss_of_match[] = {

	{ .compatible = "ti,am3356-pruss" },

	{ .compatible = "ti,am4376-pruss0", .data = &am437x_pruss0_data, },

	{ .compatible = "ti,am4376-pruss1", .data = &am437x_pruss1_data, },

	{},

};

MODULE_DEVICE_TABLE(of, pruss_of_match);

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